The candidate will streamline his future career plan to focus a substantially greater proportion of his efforts on cardiovascular disease (CVD) risk. He will extend his work in body composition to include its relationship to exercise training, genetics and plasma lipoprotein lipid profiles. The "Mentored Patient Oriented Career Development Award" will free the candidate from clinical and administrative work, allowing him continued interaction with an accomplished cadre of senior investigators, and to gain additional laboratory and research experience. He will undergo didactic educational, as well as practical experiences, in exercise physiology, lipid metabolism, genetics of CVD and the ethical conduct of research. The knowledge acquired during the period of support will help improve the medical care and overall health of older persons, and prepare the candidate for an R01 grant. Recent studies show that Whites with the APO E2 genotype had greater HDLC and HDL2-C increases with exercise training than Whites with the E4 genotype. APO E2 and E4 frequencies vary between ethnic groups, with Blacks having more E2 and E4 alleles than Whites. Moreover, a number of studies show that Blacks have higher HDL-C than Whites. In support of this, the candidate's preliminary data showed higher HDL-C and lean body mass in Blacks than Whites. After controlling for the effect of lean body mass, there were no longer any differences in HDL-C between Whites and Blacks. These observations suggest that differences in lean body mass between Blacks and Whites may contribute to their differences in HDL-C and HDL2-C levels. This led the candidate to propose the following hypotheses: 1) Older Black men and women with the APO E2 genotype will have greater HDLC and HDL2-C increases with exercise training than Blacks with the APO E4 genotype; 2.) Within the different APO E genotype groups, older Black men and women will have greater increases in HDLC and HDL2-C levels with exercise training than Whites; and 3) After accounting for differences in initial lean body mass, Black men and women will have similar increases in HDLC and HDL2-C levels in response to exercise training as Whites with the same APO E genotype. Older Black volunteers will be screened prospectively based on APO E genotype. After screening and dietary stabilization, baseline plasma lipoprotein lipids, body composition, intra-abdominal fat and VO2max will be measured. Subjects will repeat all initial testing after completing 6 months of supervised endurance exercise training. Results consistent with these hypotheses would be beneficial in identifying Blacks who will derive maximal benefit from exercise training via increases in HDLC and HDL2-C and facilitate the prescription of cost-effective exercise training designed to reduce CVD risk and mortality.